To amend the Clean Air Act requirements relating to gasoline to prevent future supply shortages and price spikes in the gasoline market, and for other purposes.

Amends the Clean Air Act to allow the Administrator of the Environmental Protection Agency to approve a provision in a State implementation plan controlling or prohibiting the use of a motor vehicle fuel or additive only if such control requires the use of either Federal clean burning gasoline (regarding which the Administrator is directed to establish requirements under this Act, replacing those for fuel currently called "reformulated gasoline") or low Reid Vapor Pressure (RVP) gasoline (as defined in this Act) for use during the high ozone season. Permits previously approved plan provisions effecting such controls to remain in effect for four years after enactment of this Act only if the State reevaluates the provisions and establishes that their benefits in terms of air quality improvement, consistent supply, production costs, and stable prices exceed the benefits of modifying them to require the use of Federal clean burning fuel or low RVP gasoline.

Repeals reformulated gasoline oxygen content requirements.

Prohibits, effective January 1, 2007, the introduction into commerce of any fuel containing methyl tertiary butyl ether.

Requires that, beginning in 2004, gasoline sold in the United States be comprised of a specified percentage of renewable fuel (ethanol or biomass-derived fuel or other fuel used to reduce the quantity of fossil fuel present in gasoline). Provides for adjustment of such percentage in a State and a program of credits for use and exchange by refiners, blenders, and importers. Expresses the sense of Congress in support of the promotion of ethanol as the primary renewable fuel.

Directs the Administrator to conduct a study of emissions and air quality changes attributable to this Act's amendments.